How does chronic emphysema typically affect spirometry readings?

Chronic emphysema is characterized by damage to the alveoli and airways, leading to airflow limitation. This condition results in several specific changes in lung function that can be measured using spirometry.

The important aspects to highlight regarding spirometry in chronic emphysema include an increase in total lung capacity (TLC) due to hyperinflation, where the lungs retain more air than normal because they cannot fully empty. This hyperinflation occurs because of the loss of elastic recoil in the lungs, causing air trapping during expiration.

Additionally, forced expiratory volume in one second (FEV-1) is typically decreased in emphysema, reflecting the obstructive nature of the disease. The ratio of FEV-1 to forced vital capacity (FVC) is also reduced.

These characteristics explain that the correct answer reflects the typical spirometry findings in chronic emphysema, where total lung capacity increases due to air trapping, and FEV-1 is decreased as the ability to force air out is impaired. Thus, the significant changes seen in a patient with chronic emphysema are consistent with the answer provided, which notes increased total lung capacity and decreased FEV-1.